Field of the Invention
The present invention relates to a display apparatus, a gradation correction map generating device, a gradation correction map generating method, and a program.
Description of the Related Art
For a display used in medical use or graphic design services, display characteristics that reproduce uniform color over an entire screen are required.
In Japanese Unexamined Patent Application, First Publication No. 2007-219062, a technique that visually corrects display unevenness in order to equalize the display characteristics has been described as a related art.
Moreover, a human image frequently has a vertically long size, and some medical users or graphic users frequently use a display apparatus in a vertical screen (Pivot function) by rotating the display apparatus. Because the display apparatus has been made thinner and lighter to improve installation flexibility, there are increasing needs to rotate the display apparatus from horizontally long to vertically long.
However, in the above-described-display unevenness, the state of display unevenness changes depending on rotation processing of the display apparatus.
By rotating the display apparatus from horizontally long to vertically long, hot air stagnates in an upper part of the display apparatus. Therefore, temperature distribution in a display screen of the display apparatus changes due to rotation of the display apparatus, thereby changing brightness and chromaticity at each point in the screen.
That is to say, as the temperature increases due to the hot air stagnating in the upper part of the display apparatus, luminous efficiency of the fluorescent material of the backlight decreases due to temperature dependency of the backlight light source, so that brightness at each point in the screen decreases, and chromaticity changes to blue.
Moreover, by rotating the display apparatus, a portion being a high-temperature portion changes in the display screen, and hence, adjustment of temperature unevenness in every direction of the screen is difficult.
At the time of adjustment, an optical measuring instrument dedicated for measurement of the display screen, and a darkroom in which the display apparatus is arranged at the time of measurement are required as factory equipment that produces the display apparatus. Moreover, after rotating the display apparatus, an aging time until the temperature becomes a stable state in which the temperature at the high-temperature portion does not change is required (for example, one hour is required for each direction of the display screen), and hence, adjustment per display apparatus takes time.
Accordingly, in a busy factory, variations in the aging time occur in the adjustment by each worker, and the degree of adjustment is different for each display apparatus. On a user side, when the user adjusts the display unevenness in the rotation of a display unit (performs unevenness correction described later), it is difficult to perform sufficient adjustment of display unevenness because the user does not have the optical measuring instrument dedicated for measurement of the display screen, nor the darkroom in which the display apparatus is arranged at the time of measurement.